Electric Cars Become Power-Grid Batteries

Imagine a car that runs quietly, burns no gas, produces no emissions, stores renewable energy, and sometimes even pays you back.

Seem like a pipe dream? Soon it won’t be. Vehicle-to-grid technology allows networks of electric vehicles (EVs) to function like a giant battery with an intelligent software interface feeding power from car to grid or grid to car on an as-needed basis. It’s now one step closer to U.S. commercialization.

American cars sit parked and unused for an average of 23 hours per day, and the storage capacity of our current electrical grid infrastructure is limited at best. This inspired vehicle-to-grid (V2G) pioneer Willett Kempton at the University of Delaware (UD) to develop the ‘vehicle as power storage’ concept in 1997 with Vermont’s Green Mountain College economist Steve Letendre. Kempton has since taken V2G from idea through proof of concept to commercial pilots in both Delaware and Denmark.

Kempton sold the international license for the technology to the Danish company Nuuve in June of 2011. Now in Delaware, the U.S. license has been purchased by New Jersey-based NRG Energy. The new business partnership between NRG and the University of Delaware (UD), known as “eV2g,” was announced with fanfare on September 26th, and featured a visit to the UD’s Newark campus by U.S. Senator Chris Coons.

At the UD announcement, Kempton humorously referred to Thomas Edison?’s famous statement that genius is 1% inspiration and 99% perspiration, saying, “I think he underestimated the amount of perspiration required”. His remark is justified. It’s been more than a decade of perspiration following inspiration for Kempton in his journey to make V2G technology a reality. Noting that Newark, Delaware, was the site of a busy Chrysler tank factory during the Korean War?, Kempton says his vision is a “post-petroleum repurposing of this facility.”

Despite the announcement, the ability of EV owners to register for the eV2g service is still two to three years away, according to NRG Communications Director Lori Neuman. Initially conceived as a technological service that will be available to EV fleet operators, eV2g eventually plans to roll the service out to individual EV owners. Kempton estimates eV2g electricity regulation services could earn $10,000 per car in revenue over the lifetime of an EV, offsetting these vehicles’ currently high purchase costs.

Vehicle-to-grid is a technology that promises to provide the short bursts of back-and-forth power used to correct imbalances in the electric power grid, explains Kempton, adding that in future, the technology may also prove useful in smoothing out the fluctuations inherent in renewable energy production such as wind and solar power.

Wind generated power production, for example, is often greatest at night, when demand for power is typically low. In our current power grid there is limited capacity for power storage, so any nocturnally generated wind energy above and beyond what’s used immediately goes to waste. V2G is an obvious solution, at least in part, for storing that power, and then drawing on the stored electricity during periods of high power demand.

Nobel laureate and physician Albert Szent-Györgyi once said, “Discovery consists of seeing what everybody has seen and thinking what nobody has thought”. Kempton epitomizes this key to technological and scientific innovation. During the birth of the automotive industry, vehicles were never conceived of as potentially being part of a national electrical grid. “They evolved on disparate paths and really didn’t connect,” said U.S. Senator Coons at the UD NRG announcement.

“You’ve got automobiles powered by petroleum, individually owned, highly mobile, free-standing, independent, and dramatically under-utilized, and then you’ve got the base-load mostly coal-fired national grid, that increasingly has strains and demands on it,” remarked Senator Coons, applauding the new potential for connectedness between energy and transportation.